Conversion of units
Conversion of units refers to conversion factors between different units of measurement for the same quantity. Techniques Rounding of results The process of making a conversion cannot produce a more precise result than the original quoted figure. Appropriate rounding of results is normally performed after conversion. (See significant figures). Multiplication Factors Conversion between units in the metric (SI) system can be discerned by their prefixes (for example, 1 kilogram = 1000 grams, 1 milligram = 0.001 grams) and are thus not listed in this article. Exceptions are made if the unit is commonly known by another name (for example, 1 micron = 10−6 metre). For a full listing of multiplication factors, see SI prefix. Table Ordering Within each table, the units are listed alphabetically, and the SI units (base or derived) are highlighted. Tables of conversion factors This article gives lists of conversion factors for each of a number of physical quantities, which are listed in the index. For each physical quantity, a number of different units (some only of historical interest) are shown and expressed in terms of the corresponding SI unit. Length Area Volume Plane angle Solid angle Mass Notes: * See Weight for detail of mass/weight distinction and conversion. * In this table, the unit gee is used to denote standard gravity in order to avoid confusion with the "g" symbol for grams. In physics, the pound of mass is sometimes written lbm to distinguish it from the pound-force (lbf). It should not be read as the mongrel unit "pound metre". Density Time Frequency Speed or velocity A velocity consists of a speed combined with a direction; the speed part of the velocity takes units of speed. Flow (volume) Acceleration Force See also: Conversion between weight (force) and mass Pressure or mechanical stress Torque or moment of force Energy, work, or amount of heat Power or heat flow rate Action Dynamic viscosity Kinematic viscosity Electric current Electric charge Electric dipole Electromotive force, electric potential difference Electrical resistance Capacitance Magnetic flux Magnetic flux density Inductance Temperature Information entropy Often, information entropy is measured in shannons, whereas the (discrete) storage space of digital devices is measured in bits. Thus, uncompressed redundant data occupy more than one bit of storage per shannon of information entropy. The multiples of a bit listed above are usually used with this meaning. Other times the bit is used as a measure of information entropy and is thus a synonym of shannon. Luminous intensity The candela is the preferred nomenclature for the SI unit. Luminance Luminous flux Illuminance Software tools Home and office computers come with converters in bundled spreadsheet applications or can access free converters via the Internet. Units and measurements can be easily converted using these tools, but only if the units are explicitly defined and the conversion is compatible (e.g., cmHg to kPa). Free conversion software * Units (software), a popular cross-platform command-line utility * Converter, contextual unit converter for Mozilla Firefox browsers * Converber, portable application converting utility * calculla calculla - online web converters * iMetrix - unit converter for xp * Unit Converter Add-in for Excel - allow a large selection of unit conversions within the Microsoft Excel spread sheet program. * uniteasy online scientific unit conversion * Unit Converter simple and extensible unit converter General commercial sources of converters *Advanced electronic calculators have unit-conversion functionality. *Spreadsheet programs usually provide conversion functions or formulas or the user can write their own. *Commercial mathematical, scientific and technical applications often include converters. See also *Accuracy and precision *Approximate conversion of units *English units *False precision *Imperial units *International System of Units *Mesures usuelles *Metric system *Significant figures *Temperature conversion *United States customary units *Units conversion by factor-label *Units of measurement References based on the wikipedia page (This page is used to help explain terminology used in Tractor Wikis main article pages) as part of the Glossary Index of terms. : External links *British law: Units of measurement regulations 1995 *ConvertBuster Variety of conversion tools to convert easily. *[http://www.unc.edu/~rowlett/units/ How Many? A dictionary of units of measurement] *NIST: Fundamental physical constants — Non-SI units (PDF) *NIST Guide to SI Units Many conversion factors listed. *Online Conversion Calculators Very extensive list of conversions from-to equvalent units. *The Unified Code for Units of Measure *Units, Symbols, and Conversions XML Dictionary Category:Units of measure Category:Metrication Category:Glossary